Syntheses of Alkylidene l-Aminoalkylidene malonates

Isopropylidene aminomethylenemalonate was prepared in 55% yield in the reaction of ispropylidene methoxymethylenemalonate (420) and ammonia in ethanol at ambient temperature for 12 hr (67M564). Wentrup et al. obtained isopropylidene aminomethylenemalonate similarly (88JA-1337). 

Meldrum s acid (421) was reacted with an excess of ethyl orthoformate by heating on a water-bath for 2 hr. A two-fold excess of the appropriate 

Isopropylidene methoxymethylenemalonate (420) was reacted with amines in boiling cyclohexane for 24 hr, or in acetonitrile at 20°C for 5-30 min, to give aminomethylenemalonates (423) in 40-99% yields [86JCS(P1)1465 88JCS(P1)863, 88JCS(P 1)869], 

Isopropylidene methoxymethylenemalonate (420) was reacted with amino esters, amino acids, and dipeptides at 95-100°C to give rise to the corresponding isopropylidene aminomethylenemalonates (424) in 54-85% yields (85MI3 86YZ154). 

The reactions of isopropylidene methoxymethylenemalonate (420) and anilines at reflux temperature for 3-7 hr gave arylaminomethylenemalo-nates (425) in 62-92% yields (85SC125 87T4803). 

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